3. make the following sentences interrogative and negative. 1. i can discuss your paper after lunch. 2. you must meet him at the station. 3. the student may keep the book till monday. 7. you should help your brother. 5. he had to go home after the meeting. 6. she will be able to do this work herself. 7. they had to be at the hospital at six. 8. he was able to play football yesterday. 9. we should speak english in class. 10. helen could read a book at the age of five.

1. Can I discuss your paper after lunch? I cannot discuss your paper after lunch. 
2. You must not meet him at the station. Must I meet him at the station?
3. The student may not keep the book till Monday. May the student keep the book till Monday?
4. You should not help your brother. Should I help my brother?
5. He had not to go home after the meeting. Had he to go home after the meeting?
6. She will not be able to do this work herself. Will she be able to do this work herself?
7. They had not to be at the hospital at six. Had they to be at the hospital at six?
8. He was not able to play football yesterday. Was he able to play football yesterday?
9. We should not speak English in class. Should we speak English in class?
10. Helen could not read a book at the age of five. Could Helen read a book at the age of five?